trust96xj

I've had a cel for as long as I can remember. O2 sensor out of range. Replaced them. Nothing. Does a 96 Cherokee sport 4.0 have an o2 sensor fuse or relay or anything? I'm kinda lost. This is stumping me hard. And after a reset on the comp it took 98 miles for the cel to turn back on. Someone help!

trust96xj

Also, have a non Cali made jeep. Only two o2 sensors.

CCKen

I think the '96 had an O2S heater fuse like later XJ's in the PDC. It's a 15 Amp fuse. Here's a pic of the '98/'99 PDC and the O2S fuse. It may be the same for a '96. Check it out.

trust96xj

Yea I can't find one for 96 and mine looks different. None of my fuses appear to be bad, I'm not sure what to do as of now. I've teplaced both o2's and it hasn't been fixed. And I can't find a diagram for a 96.

VTJeep

The diagram won't help ya... I think... It's probably a different issue. Ive had an issue with my XJ since I bought it where it will hesitate and pop (backfire) at manifold. The CEL never kicked on, but finally we got codes saying the o2's were gettin irregular voltage, etc..
Replaced both o2's, issue persists.
Replaced again, issue persists.
I've done more than just replace the o2's, too.. It's been everything except:
-ECM
-Alternator
-Injectors
-MAP sensor
There's probably a bad sensor or computer (hopefully not the ECM, ~$350) that is causing the issue. Have you put it on a code reader/diagnostics machine? Even if CEL isn't on, codes can be stored in there that will give you a direction.

CCKen

That O2S heater fuse shown in the PDC photo does apply to your '99...did you check it?

CCKen

I have wiring diagrams for a '94 and a '97 but nothing in between. I think the '94 may only have one O2S and it's OBDI. Your '96 O2S's have to be heated sensors. There has to be a fuse somewhere in your Jeep. Does the '96 have a Junction Block? Maybe it's in there.

Wish I could help ya out bud.

rrich

It's NOT the sensor's fault! Get a scanner on that can read what the sensor is doing. Very likely either an intake or exhaust leak.
The code is telling you the sensor voltage is pegged, up or down.

FL Denmark

the error say "sensor out of range"
that means that the sensor is doing its job, but something else is causing it to reach its limits.

therefor the problem can be either your engine is running to rich or its running to lean.

the best thing and the cheapest thing would be a trained mechanic with a live data tester to have a look at it.

otherwise you can replace spareparts in blind and ues a fortune on that.

good luck with it.

Gorillaxj

It could also be a short, I have seen the wire harness melted under the intake to the sensors throwing 02 codes...

But I would agree, If you replaced the sensors and everything looks in place to you take it somewhere as throwing parts at it could cost you more in the long run. And on a vehicle with 2 sensors the b1s1 sensor adjusts your fuel trims and helps fine tune the engine while driving... I wouldn't ignore it for long if its a sensor 1 code.

trust96xj

I've ran a code reader and all it tells me is that the o2 is out of range. I don't have a live sensor reader, though. What's an easy and safe way to check an exhaust/intake leak?

trust96xj

Yea I've looked at every damn fuse in the thing and not one is burned out. I don't believe I have an exhaust or intake leak cause I just replaced my manifold. I'm not sure though. I'm gonna check the voltage in the harness and everything in the morning. I'll keep y'all posted. Thanks for the help everyone. I've been trying to battle this for a good 8 months at least. And now I'm starting to get a somewhat rough idle. Yet my power and throttle response hasn't Deminished what so ever. Neither has my mpg.

rrich

"""""I just replaced my manifold."""""
Good reason to suspect a leak.

"""""And now I'm starting to get a somewhat rough idle"""""
Another sign of an intake leak.

Do a smoke test.

CCKen

Can you get the actual "P" code. Some scanners/code readers have generic teminology to describe faults. "O2 sensor out of range" does not show up in the FSM as a DTC.

trust96xj

tested it. no leaks intake/exhaust.